• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1992년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 19-21 Oct. 1992
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• pp.953-958
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• 1992

This paper deals with the solution of inverse kinematics of the industrial FANUC robot with IBM PC386. The inverse kinematics of FANUC robot cannot be solved by the algebraical method, because arm matirix T$_{6}$ is very complex and 6-joint angles are associated with the position and the approach of end-effector. Instead we fuund otehr 5-joint angle by and algebraical method after finding .THETA.$_{1}$ value by a numerical method.d.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1990년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 26-27 Oct. 1990
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• pp.62-67
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• 1990

A number of performance measures have been proposed for the quantification of dexterity for kinematically redundant manipulators. The use of such measures is especially important for kinematically redundant manipulators since they can satisfy the subtasks such as singularity avoidance and obstacle avoidance in addition to satisfying a specification of end-effector motion. In this paper, the advantages and disadvantages of performance measures proposed up to date are compared through simulations under the same environment. Besides, a new dexterity index for manipulators with multiple degrees of redundancy is proposed and shown to be effective through the simulation.

• 대한기계학회논문집
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• 제19권7호
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• pp.1581-1589
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• 1995

The feasibility of using AE for detecting contact and slip between a workpiece and an end effector has been tested. Specifically, the relationship between the contact and slip motion and the characteristics of the AE signal is theoretically and experimentally investigated. The experimental results manifest that the high sensitivity of AE signal to the contact and slip makes it a good alternative as a robot tactile sensor.

• 대한수학회보
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• 제49권3호
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• pp.635-645
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• 2012

In this study, we investigate the curvature functions of ruled surface with lightlike ruling for a null curve with Cartan frame in Minkowski 3-space. Also, we give relations between the curvature functions of this ruled surface and curvature functions of central normal surface. Finally, we use the curvature theory of the ruled surface for determine differential properties of a robot end-effector motion.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 추계학술대회논문집A
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• pp.789-794
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• 2000

This study proposes an error analysis for a cubic parallel device. There are many sources of errors in the device. An error analysis is presented based on an error model formed from the relation between the universal joint error of the cubic parallel manipulator and the end effector accuracy. The analysis shows that the method can be used in evaluating the accuracy of a parallel device.

• Structural Engineering and Mechanics
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• 제62권5호
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• pp.619-629
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• 2017

This paper focuses on the study of complete dynamic modeling and maximum dynamic load carrying capacity computation of N-flexible links and N-flexible joints mobile manipulator undergoing large deformation. Nonlinear dynamic analysis relies on the Timoshenko theory of beams. In order to model the system completely and precisely, structural and joint flexibility, nonlinear strain-displacement relationship, payload, and non-holonomic constraints will be considered to. A finite element solution method based on mixed method is applied to model the shear deformation. This procedure is considerably more involved than displacement based element and shear deformation can be readily included without inducing the shear locking in the element. Another goal of this paper is to present a computational procedure for determination of the maximum dynamic load of geometrically nonlinear manipulators with structural and joint flexibility. An effective measure named as Moment-Height Stability (MHS) measure is applied to consider the dynamic stability of a wheeled mobile manipulator. Simulations are performed for mobile base manipulator with two flexible links and joints. The results represent that dynamic stability constraint is sensitive when calculating the maximum carrying load. Furthermore, by changing the trajectory of end effector, allowable load also changes. The effect of torsional spring parameter on the joint deformation is investigated in a parametric sensitivity study. The findings show that, by the increase of torsional stiffness, the behavior of system approaches to a system with rigid joints and allowable load of robot is also enhanced. A comparison is also made between the results obtained from small and large deformation models. Fluctuation range in obtained figures for angular displacement of links and end effector path is bigger for large deformation model. Experimental results are also provided to validate the theoretical model and these have good agreement with the simulated results.

• 로봇학회논문지
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• 제6권2호
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• pp.130-140
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• 2011

This paper proposes an optimal posture for the task-oriented movement of dual arm manipulator. A stability criterion function which consists of three kinds of feature-representative parameters has been utilized to define the optimal posture. The first parameter is the force which is applied to the object. The torque of each joint and position of arm are attained from the current sensor and encoder, respectively. From these two data, the applied force to an object is estimated using sum of vectors of the joint torques estimated from the measured current. In order to investigate the robustness of each posture, the variation of the end-effector from the encoder information has been utilized as the second parameter. And for the last parameter for the optimality, the total energy consumption has been used. The total consuming energy of each posture can be computed from the current information and the battery voltage. The proposed robot structure consists of a mobile inverted pendulum and dual manipulators. In order to define the optimal posture for the each object, external disturbances are applied to the mobile inverted pendulum robot and the first and second parameters are investigated to find the optimal posture among the pre-selected most representative postures. Finally, the proposed optimal posture has been verified by the proposed stability criterion function which consists of total force to the object, the fluctuation of the end-effector position, and total energy consumption. The effectiveness of the proposed algorithms has been verified and demonstrated through the practical simulations and real experiments.

• 대한기계학회논문집A
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• 제40권3호
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• pp.289-296
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• 2016

본 연구에서는 공압인공근육을 구동부로 가지는 내부형 연속체로봇의 기구학을 제시한다. 연속체로봇 단일마디는 세 개 인공근육의 병렬구조로 구성되며, 각 인공근육은 가해지는 공기압력에 의해서 독립적으로 수축하여 근육의 한쪽이 부착된 기준 마디절에 대해서 근육의 다른쪽이 연결된 원격의 마디절의 공간상 운동이 발생한다. 인공근육의 굽힘형상을 고려하여 원격 마디절 중심에서의 방위와 위치를 예측하는 기구식을 유도하였으며, 단일 마디를 여러 층으로 적층하였을 때 로봇 말단장치에서의 방위와 위치도 변환행렬의 곱으로 제시한다. 그리고 인공근육의 길이/압력 변화에 따른 말단장치에서의 속도를 계산하는 자코비안 행렬을 구동부의 위치배열을 고려하여 유도하였고 실제 실험을 통해서 제시한 기구식의 유효성을 검증하였다.

• 제어로봇시스템학회논문지
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• 제22권8호
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• pp.590-596
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• 2016

Biopsy is a typical needle type intervention procedure performed under radiographic image equipment such as computed tomography (CT) and cone-beam CT. This minimal invasive procedure is a simple and effective way for identifying cancerous condition of a suspicious tissue but radiation exposure for the patients and interventional radiologists is a critical problem. In order to overcome such trouble and improve accuracy in targeting of the needle, there have been various attempts using robot technology. Those devices and systems, however, are not for full procedure automation in biopsy without consideration for tissue sampling task. A robotic end-effector of a master-slave tele-operated needle type intervention robot system has been proposed to perform entire biopsy procedure by the authors. However, motorized sampling adopted in the device has different cutting speed from that of biopsy guns used in the conventional way. This paper presents the design of a novel robotic mechanism and protocol for the automation of biopsy procedure using spring-triggered biopsy gun mechanism. An experimental prototype has been successfully fabricated and shown its feasibility of the automated biopsy sequence.

• 한국전자통신학회논문지
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• 제15권2호
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• pp.273-284
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• 2020

본 논문은 현재 자동화 공정에서 널리 쓰이는 델타 로봇을 저가형 DC 모터로 제작 및 제어하는 방법을 제안한다. 델타 로봇의 기구학 및 동역학을 해석하여 시뮬레이션을 한 후, 이를 기반으로 저가형 DC 모터를 선정하였다. 실험을 통하여 모터의 특성 값들을 획득하고 제어 이론을 적용하여 전류-위치 Cascade 제어 시스템을 설계하였다. 설계한 시스템의 성능을 검증하기 위해서 델타 로봇의 말단효과장치의 목표 경로를 설정하여 실험을 진행하였다. 실험을 통하여 저가형 모터를 사용함으로서 발생하는 문제점들을 보상 알고리즘을 설계하여 극복하고 End-effector의 위치 제어 성능을 입증하였다.